The present invention relates to methods and devices for transporting of various materials in general. More particularly, the invention relates to a method and device for transporting the materials in the powdered, fine-grained or coarse-grained state.
Such devices as blast apparatus are known for material injection, backfilling and building of dams in underground mines. Such blast machines have been utilized with devices for transporting construction materials. The transporting device usually includes storage bins or storage containers from which construction materials are transported through relatively long screw conveyors to a work site. In such machines the material feed line is usually composed of a number of identical storage containers positioned in series one after another and at a distance from each other. The screw conveyor of approximately seven meters or more is arranged in a tubular housing located below those storage containers whereas each storage container is connected to the tubular housing by an opening which may be closed by a slide. A drive for the screw conveyor located in the close vicinity of the storage containers includes a motor, a gear unit and a coupling arranged on a floor of the seam in the mine. Since the screw conveyor must be positioned at the area facing its drive station it can discharge the material only downwardly. However, there is a requirement in ground works that in order to provide for a sufficient space for conveyor throughput on the floor of the seam the material discharged from the inclined conveyor, and particularly the screw conveyor, should be transported pneumatically in the upward direction so that the construction material then falls and is processed to a suitable blast machine in the known fashion.
A disadvantage of such known devices is first in that the blast machine, storage containers and drive stations with the conveyors are practically immovable which renders further construction operation difficult. The whole installation is therefore bulky, and the space usually required for such an installation is insufficient because the drive station and the screw conveyors positioned below the storage containers require a great deal of space. Moreover, it is required in ground works that the throughput of the screw conveyor should be obtained within the space on the floor of the seam. This requires considerable space. Due to the fact that in underground construction works some other conveying means can also function in the region of the above-described transporting device such a bulky installation often causes considerable difficulties. In order to overcome the disadvantages of such bulky installations and make construction works in the mine possible it has been suggested to increase air pressures in the blast machine and/or increase tube dimensions in the pipes between the blast machine and the outlet of the conveyor. However, even with all above suggestions the installation is not always efficient.
A further disadvantage of conventional constructions of material-transporting devices is that although screw conveyors if efficiently used are rather inexpensive they are sensitive to the change of the grain size of the construction material being transported because the screw conveyors are usually designed for a certain material. If the material to be transported is changed to the material having a different grain size this can result in an operation disorder caused by clogging of the conveyor. In such cases, particularly when conveyors are located below the storage containers and very long screw conveyors are utilized the clogging can lead to the blocking of the whole installation. This is also possible in the inclined conveyor operating with one screw conveyor. Furthermore, the material being conveyed must pass through the whole length of the screw conveyor. Long screw conveyors, however, tend to bend, which makes their use rather limited.